1. Field of the Invention
The instant invention relates generally to idler rolls and idler roll sets; and more particularly to a simplified device and construction for the ends of hollow idler roll shafts to facilitate attachment thereto of either a threaded grease fitting, or a tube interconnecting the shaft of one idler roll to the shaft of an adjacent idler roll for feeding grease therethrough.
2. Prior Art
Numerous attempts have been made to design a lubrication system which will effectively lubricate the entire series of three or more idler rolls when a grease gun is applied to a fitting situated at one end of the series of rolls. In addition to possessing the ability to effectively distribute the lubricant, the system must be flexible to permit the angularity of the adjacent rolls to be altered without impairing the communication between adjacent rolls.
One attempt to realize these goals is set forth in U.S. Pat. No. 3,338,381, granted Aug. 27, 1967 to Philip J. Imse. Such patent utilizes a pair of short resilient tubular members retained in operative position within a unique split housing to establish communication between the hollow central shafts of adjacent rolls. Radial ports in the shaft of each roll in the series of rolls permit a limited quantity of the lubricant to flow outwardly and lubricate the bearings situated at the opposite ends of the shaft for each roll.
However, to secure the resilient tubular members to the end caps on the opposite ends of the hollow shaft passing through each roll, cooperating screw threads must be formed between the exterior surface of the tubular members and the walls of the axial passage in the end cap into which the member is inserted. Forming threads on the exterior surface of a flexible tubular member while maintaining its concentricity is a difficult chore, and if the execution is faulty, the flexible member may slip out of the end cap as the rolls are replaced or adjusted relative to one another. Also, the split-housing requires a captive screw for retaining the pair of tubular members in operative relationship. Such construction, therefore, requires that additional components be stocked for inventory, thus adding an undesirable cost factor to the maintenance and operation of the idle roll set.